Resin of sulfur dioxide and an unsaturated organic compound which reacts to form a heteropolymeric resin



19, 1952 w. w. CROUCH ET AL 2,607,752

' RESIN 0F SULFUR DIOXIDE AND AN UNSATURATED ORGANIC COMPOUND WHICH REACTS TO FORM A} HETEROPOLYMERIC RESIN Filed Jain. 2, 1951 RE-ACTOR STRIPPER 1 I4) Pk I ADJUSTER PLASTICIZER INVENTOR. w.w. CROUCH J.F. HOWE BY A TTORNEVS Patented Aug. 19, 1952 RESIN OF SULFUR DIOXIDE AND AN UNSAT- URATED ORGANIC COIWPOUND WHICH REACTS TO FORM A HETEROPOLYMERIC RESIN Willie W. Crouch'and John F. Howe, Baruesviue,

kla., assignors to Phillips Petroleum Company, v

a corporation of Delaware Application January 2, 1951, Serial No. 204,068-

(01. acne-32.4)

19 Claims.

This invention relates 'to the production. of synthetic resinous materials formed by reaction between sulfur dioxide and one or more unsaturated compounds. In one of its more specific aspects it relates to the production of olefinsulfur dioxide resin compositions. In another of its more specific aspects it relates to the production of homogeneous olefin-sulfur dioxide resin compositions.

This application is a continuation-in-part of U. S. application Serial Number 129,867, filed No vember 28, 1949.

It has been well known for a number of years that sulfur dioxide will react with numerous unsaturated organic materials to form heteropolymeric resinous products. Apparently the resin is produced from equimolar quantities of sulfur dioxideand the unsaturated organic material. The reaction appears to take place only in the liquid phase and'it will proceed in the absence of catalysts only in the presence of actinic light, or it will proceedin the presence of any one of a large, number of catalytic materials, most of which appear to have oxidizing properties, in the dark or in the light, Some of the more important catalysts'for promoting this reaction are oxygen, hydrogen, peroxide, ozone, various nitrates such as silver ad lithium nitrates, nitrites, persulfates, chlorates, perchlorates, ascaridole,

' ozonized olefins, etc. Organic compounds which enter into the formation of such resins include mono-olefins, cyclo-olefins, substituted aliphatic olefins such as styrene, diolefins such as butadiene, isoprene, cyclohexadienejand the like, acetylenes and polyfunctional unsaturated com-: pounds such as allyl alcohol, vinyl acetate, allyl ethyl ether, ortho-allylanisole, ortho-allylphenol, paraebromoallylbenzene, methyl undecylenate, undecylenyl alcohol, undecylenic .acid, etc. Whenmixtures of such unsaturated organic com poundsare used, the resulting resin appears to have been formed by a copolymerization of the unsaturated compounds with sulfur dioxide since its properties do not correspond to blends of resins produced from the individual unsaturated organic compounds and often have properties which are superior to any one of the resins produced from the individual unsaturated compounds. For many of the unsaturated'compounds there appears to be a .ceiling temperature above which the reaction does not take place, and in such instances it .is necessary to conduct the resinforming reaction at a temperature below the ceiling temperature and, when forming the resin from a mixture of organic unsaturated compounds, it appears desirable to conduct the reaction at a temperature below the ceiling temperature of the material having the lowest ceiling temperature. The resin-forming reaction is somewhat exothermic and generally some pro- 2 vision must be made for removing the, heat of reaction. All of these features. are more fully described in the literature. I I

, Olefin-sulfur dioxide polysulfones. are inherently relatively inexpensive, usually thermoplastic resins, compatible with many other polymeric materials, and are potentially useful in numerous applications for which much more expensive resins are presently employed. Commercial development of. olefin-sulfur dioxide resins has heretofore been considerably delayed, largely because of their brittleness and tendencies to crack and to shatter on breaking. Broadly speaking, this invention comprises forming olefin-sulfur dioxide resin compositions by plasticizing and stabilizing olefin-sulfur dioxide resins and resin latices having pI-Iivalues not greater than 8, with a nitrile. The compositions of our invention are superior for many applications to unplasticized and unstabilized olefin-sulfur dioxide resins.

Utility of these resins has in the past been limited in part because of theirlack of thermal stability, i. e., resistance to decomposition by heat, attemperatures such as from 200? Ffto 500 F. Accordingly, these'resins often cannot be employed satisfactorily in the production of molded articles. 'On beingexposed to temperatures as high as 200 F. orhigher over a short period, for example 1,110 3 hours, decomposition of the heteropolymer takes place to liberate sulfur dioxide and initial unsaturate reactant. The resin thus becomes porous and somewhat ..voluminous and is undesirable for the use for which it was intended. We have found that olefinsulfur dioxide resins are very appreciably stabilizedby adding a nitrile thereto as more fully disclosedhereinaften. They are less brittle and more resistant to cracking and to shattering on breaking. In many cases theyare flexible and completely resistant to shattering.

An object of this invention is to mix olefinsulfur dioxide resins with nitriles to formimproved olefin-sulfur dioxide resin compositions. Another object of the invention is to produce homogeneous mixtures of olefin-sulfur dioxide resins and nitriles to form flexible resin compositions. Another object of this invention is to provide an improved method for producinghomogeneous, stable latices of plasticized olefin-sulfur dioxide resins. Another object of the invention is to provide afmeans and method for stabilizing olefin-sulfur dioxide resins. Other and further objects and advantages of this invention will be apparent to those skilled in the art upon study of the accompanying disclosure and discussion.

The production of materials of the polymeric type in aqueous emulsion is well known; Emulsion polymerization methods are particularly important and are widely used in the manufacture of synthetic rubber, and the like. Usually, however, the monomers employed in these processes are compounds such as butadiene; isoprene, chloroprene, methyl acrylate; methyl methacrylate, acrylonitrile, styrene, and the like; These monomers are chemically neutral, that is, they have neither strongly acidic norbasio-properties. Furthermore, most of them have little orno solubility in water so that when they are used in emulsion polymerization processes they form a water-insoluble phase which contains substan- These compounds tially' all of the monomers. I are also non-electrolytes,-that is, any partof the material that enters the water phase .is not action of the emulsifying agent.

In contrast to the abovementioned monomers,

, ionized and therefore does not interfere with the sulfur dioxide is highlysoluble in water and t I a 4 g. a plasticized olefin-sulfur :diox'ideresinin stable latex form.

The compositions of our, invention comprise between 1 and 150 parts by weight of plasticizer per 100 parts by weight of resin, preferably between 5. and parts by weight of plasticizer per 100 parts by weight of resin, the plasticizer being a nitrile having a boiling point of 250 F. or above, a molecular weight of between 80 and 1000, and the absence of any aliphatic hydrocarbon group containing more than six carbon atoms. Materials which are suitable plasticizers for this invention fall within three general classes, 1. e.,

aliphatic nitriles, aromatic substituted aliphatic nitriles, aromatic substituted aliphatic nitriles in which the aromaticringjis substituted by aliphatic'groups and cyclo aliphatic nitriles. spa-5 cific materials which are suitable plasticizers for this invention include'adiponitrile, benzonitrile, phen'ylacetonitrile, succinonitrile, valeronitrile, pentenenitrile, m-butylbenzonitrile, phenylpropionitrile, and mesitylenonitrile. Nitrile compounds which do not have the 'properties and characteristics listed above and which do .not form homogeneous mixtures with olefin-sulfur dioxide resins are exemplified by m-octylbenzonit: rile, decanenitrile, which contain aliphatic groups of more than six carbon. atoms, and acetonitrile,

I and propionitrile, which have boiling points and acid to a resin or rubber latex prepared in the usual way is known to be an eifective means of that the selected nitriles must be thoroughly and intimately mixedwith the resin. or latex. Thus for example, the nitrile stabilization agentmay be added to an aqueous dispersion of theresin in which the latter was prepared and'both the resin-and stabilizer precipitated therefrom simultaneously. The dry resin and thestabilizer can also be intimately mixed on a r011v mill. 'The stabilizer may be dissolved in methanol or other suitable solvent and thoroughly admixed .With a dry, powdered resin and the solvent subsequently removed by evaporation or other suitable means. V

The compositions of 'our invention may be produced in any suitable'manner. Olefin-sulfur dioxide resins prepared in any manner, may be plasticized by mixing the components on a roll mill, by dissolving the components in a solvent and then evaporating the solvent or, when the resin is prepared by forming a l'aqueous emulsion of the sulfur dioxide and olefin, the resulting latex can be mixed with an aqueous dispersion of the organic plasticizer. V

The last named method is oftenpreferred, By

' this method a latex of a plasticized resin is propolymericreaction product? To this latex isadded a dispersion-or emulsion of a nitrile to produce molecular weights below' those required bythis invention.

All of the above named nitriles as Well as others are suitable as stabilizing, agents of this inven tion. Stabilizing agents of this invention have the following general formula RCN'Iwh'ereiri i1 is an alkyl, cyclo'alkyl, alkenyl, hydrocarbon arc-I matic group, or substituted alkyl; cycloalkylfor alkenyl group wherein the substituents are selected from a group consisting vof a cyano radical and a halogen radical selected from the group consisting of fluorine, chlorine, andbrominaor a substituted hydocarbonaromatic wherein the substituents are selected froma group consist ing of'alkyl and. halogen radicals selectedfrom the group consistingof fluorine; chlorine, and bromine. Examples of materials which come within the definition of the above general formula, in addition to the nitriles namedlab'ove, are isocapronitrile, chloroacetonitrile, fluoroacetonitrile, bromoacetonitrile, hexadecanenitrile, and diphenylacetonitrile. v

Nitriles having physical properties falling within a range and also extending outside that defining limit for thefplasticizers are suitable as stabilizers. The stabilization agent of this inven: tion is a nitrile, described above, which has a boiling point of at least 170 F., preferably 245 F., a molecular weight of between 40 and 1000, and the absence of anyaliphatic hydrocarbon group. containing more than twenty carbon atoms. The ratio of stabilizer to resin which issatisfactorily used is 0.5: to :100. Ordinarily a ratio of 15: 100 will be suiiicient for stabilization purposes. The drawing is a schematic flow plan utilized in the preferred method of this invention.

Referring particularly to the drawing, an olefinsulfur dioxide resin latex in passed from reactor l I through conduit l2 to stripper chamber [3 where most of the excess sulfur dioxide and un reacted olefin are removed by passing steam, hot air, or the like into stripper chamber l3 through inlet conduit M and removing the stripping materials, together with th'eremoved impurities, from stripper chamber I 3 through outlet conduitl5. Impurities may be removed from olefin sulfur dioxide resins prepared. in aqueous emulsion by coagulation of the latex and subsequent water washing, filtration, and. drying of the coagulum. In order to utilize a continuous process for the preparation of our olefin-sulfur dioxide resin compositions, we prefer to use the latex. By operating in such a manner we get a better dispersion and obtain a plasticized resin in latex form. However, it has not been found possible to reduce the sulfur dioxide content to much less than 0.5 weight per cent of the latex, or to obtain .a pH much less acidic than about 1.5 by such physical means.v The purified latex is removed from stripper chamber [3 through conduit [6 and is passed into chamber I! where its pH value is adjusted by the addition of a base through conduit 18 to a value of not above 8. The latex material, the pH value of which has been adjusted, is removed from chamber I! through conduit I 9- and is passed to plasticizer chamber 21. An organic plasticizing' compound such as has been described above is 'added in the form of an emulsion or dispersion to the latex material in chamber 2| through conduit 22. The latex and the plasticizer material are mixed within chamber 2| in such proportions that the weight ratio of plasticizer to resin is, as disclosed above, preferably within the range of from 5: 100 to 80:100. The final solids content (plasticizer plus resin) concentration of the plasticized olefin-sulfur dioxide resin latex is generally within the range of from 15 to '70 weight per cent, although values from to 65 weight per cent are preferred. The plasticized latex material is removed from the plasticizer chamber 2| through outlet conduit 23.

The plasticizing step of this preferred method of operating our process generally requires the previous emulsification of the plasticizer. This may be done in any suitable manner, e. g., the plasticizer may be added to an aqueous emulsifier solution and emulsified, or a fatty acid may be dissolved in the plasticizer. and the plasticizer containing the dissolved fatty acid may be added to an aqueous alkaline solution and emulsified. In this case the emulsifying agent is formed in situ. The physical process of emulsification may be effected in any effective manner, such as by passing the mixture through a gear pump, a centrifugalpump, or a colloid mill, by turbulent flow or by agitating the materials with a paddle 'or stirrer, or by shaking in a suitable container. The term plasticizer as employed herein is used to define a nitrile material compatible with an olefin-sulfur dioxide polymer which lowers the softening temperature of the polymer and/or makes it more flexible. v q

The concentration of the plasticizer in the plasticizer emulsion or dispersion may be in the range of from 20 to 70 weight per cent. The concentration of the emulsifying agent in the plasticizer emulsion may lie in the range of from 0.2 to 5 weight per cent. Any suitable emulsifying agent or mixture of emulsifying agents may be used which is effective to produce a physically stable emulsion or dispersion. Examples of suitable emulsifying agents are the long chain alkyl sulfates and sulfonates, the aryl and alkaryl sulfonates, the fatty acid soaps, rosin acid soaps, non-ionic emulsifying agents, such as condensation products of an alkyl phenol and ethylene oxide, cationic emulsifying agents, such as salts of organic bases exemplified by amine salts, and quaternary ammonium salts; for examplaheptadecyl-amine-epichlorhydrin, dodecylamine jhy'- drochloride, and the like.

The above described four-step method of operation consisting of polymerization stripping, adjustment of the pH value of the latex, and mixing of the latex with a plasticizer emulsion is the preferred procedure for making latex; .of. ,low acidity and dissolved sulfur dioxide, content. Such a latex is preferred for most applications, such as for impregnating cloth and paper,. and for many types of surface coatings, as well as for unsupported films. It should be'understood, however, that thispreferred procedure may be modified somewhat and still yield a stable plasticized resin latex satisfactory for certain other applications or for use as a source of solid plasti cized resin through coagulation of the latex. In one modification of the invention, the addition of a base to the latex to adjust the pH value thereof may follow rather than precede the addition of the plasticizer emulsion to the latex. In some cases, however, in such a modification more emulsifier is required than in the preferred procedure so as to avoid partial coagulation of the latex on addition of theplasticizer emulsion. In asec-' ond modification of the invention, if sufiicient emulsifier is present the latex may be plasticized without adjusting the pI-L. withoutstripping the latex to remove excess sulfur dioxide,.or without doing either to give ahighly acidic latexof. a plasticized resin. .Such a. modification,.however, requires a considerably greateramount of .emulsifier than is present at. the. time. of addition of the plasticizer in the preferredprocedure. q The best olefin-sulfur dioxide resin compositions are obtained when the latex is stripped .and when the pH value thereof is adjusted so as to fall within the rangeo-f from 3 to Bbeforeplasticization. I

, The latices of olefin-sulfurdioxide resins produced as above described-.may beemployed in latex form or the latex maybe coagulated and the plasticized resin. recovered. r

Advantages of this invention are illustrated by the following examples. The reactants and their proportions and other specific ingredients of the recipes are presented as being; typical and should not be construed to limit theinvention unduly.

' v EXAMPLE'I Three l-butene-sulfur dioxide resin compositions containing nitrileswere prepared in'the following manner. .A' 10 weight per cent solution of the resin and 30' weight per cent acetone solu tions of the nitriles were prepared. Portions of the resin solutions were thoroughly mixed with individual nitrile solutions proportions such that the resin and the nitrile were in proportions Within the range set forth above. Each solution so prepared was then poured on a Watch glass and the acetone slowly evaporated from it. The solid film so produced 'was in all cases clear and transparent, which indicated a homogeneous film. Results of the routine tests aresetforth in Table I.

TABLE I w s A lbutene-sulfur dioxide pared. by polymerization according to the following. recipe:

' I Partsbyweiight l-butene p 46.7 smrur'dioxme 883' Lithinntnitrate 0.5 Sodium alkyl sulfate". emulsifier 2.0 Water 120.0

The; reactlon mlxturewas agitated forv four hours at aztemperatureof 77 F. The latex was stripped in; a column: to remove most: of the unreacted sulfur dioxide- Itwas then stabilized with 8. parts of. afiveper cent aqueous alkyl sulfate emulsifier solution per 100- parts of latex, and

' thepH wasadiustedto a-value of 4.3 with a. seven per: cent: aqueous ammonia solution. The latex then. had a-solidscontentot 37.5 weight per cent.

'An emulsion of a-plasticizer was prepared using the following recipe:

. Parts by weight Plasticizer 100 Oleic acid 1.9

Ammonia. 0.15

Water 51.8

mam

every 100 parts of resin. The plasticized resin latex so" formed was stable. A film of the plasticized resin was formed by spreading a sample of An olefin-sulfur dioxide resin was prepared by aqueous emulsion polymerization, employing the following recipe:

Parts by weight Olefin blend 57.7 Sulfur dioxide 88.3 Water 180 Ammoniumnitrate 0.5 Maprofix MM 0.6

. The olefin blend had the following composition:

' M01 per cent n-Butane 1 lso-butane v 'Ca (propane-prop lene) Iso-hutylene l -buten'e I 2-butene-ci's 2-butene-trans 'Butadiene Sodium lauryl sulfate dispersing agent (in the form 0f 8. paste containing about 60' per cent solids).

The polymerization was conducted for a period of '7 hours and a 95 percent. conversion was ob- H our-wager:

tained, based onthe totalolefins added. The

resin was 'preparedfromthe latex and dried ac- 8 cording to conventional procedure. The stabiliz ers indicated. in the. table below were added in indicated percent by weight of dry resin and the per cent decomposition was determined; as follows:

Two grams. of the. stabilizer=treated resin were placed in a suitable test tube. which was then partially immersed in a constant temperature bath held at 325:2" F: for varying periods. Per

cent loss in weight of the resin was determined at the end of indicated heating periods. The per cent loss in weight provides a measure of the thermal decomposition which took place. Untreated controls were run simultaneously with the'tests.

Results of the tests arev recorded in Table II below.

Addition procedures l. Dissolve stabilizer in methanol and apply to dry resin. followed by evaporation of methanol.

2. Dissolve 2' grams stabilizer in. benzene and emulsify mixture in 30 grams of 1% Orvus 1 solution (aqueous). Emulsion so formed added. to

acid, latex.

' Table II 7 Per cent loss iii-Weight at End'ofzx Hours Methodj Added Heating 2.17325 i2 F Control... 7.3 .109 15.1 29.0 1 Diphenylacetonitrile,.2% 1.2 2-3 3. 4.2 l Diphenylacetonitrile, 1%. 2.5 3.7 4:3 5.7 2 Diphenylacetonitrile,2% 3.2 4L3 5.1 613 HOURS Control 6.0 9.2 ice 7 I Diphenylacctonitrii'e. .5% 6. 3' 8L7 1.4.5

Control.-. 8.1 10.8 16.6 1 I5ooapron1tr1le(C7H 'CN'). 2% 5.7 I 7.7 11.7 1 Benzonitrile,2 3.9 5.3 8.2 1 Suc'cinonitri1e,2% 2.1 3.4 6.2 1 Adiponitrile, 2% 4.5 7.5 12.2 Control 6.0 9.2: 16.8 1 Chloroacetonitrile',2%- 2.7 3.9 7.2 l Hexadecanenitrile, 2%. 5.0' 7.3 13.3' Gontr l 5.6 8.9- 15:1 ll 1 Benzon1trile,0;5% 3.8 5.6 0.2 l Bell'zonitrile,.l%- 416 6:3 9.0 W l Chloroacet0nitri1e,0.5%., 4-7 7.6 -12.4 l Chloroacetonitrile', 1%. 3.9 6.4 10. 8' l Succinonitrile,,0.5%- 4.8 6.6 10.1 l Succinonitrile, 1%.... I 41.5 6.2 9. 4'

EXAMPLE v A l-pentene resin was prepared according to the following recipe:

Parts by weight L-pentene -c 46.7 Sulfur dioxide 88.3 Maproflx MM 0.6 Ammonium. nitrate 0.5 Water 1 Sodium lauryl sulfate.

this test. Results are set forth below in Table III.

Table III Per cent loss in Weight at End of x Hoursv Heating at 325 =l=2 F Control 5. 3 7. 2 10. 4 Dlphenylacetonitrile, 2% 3. 4 4. 3 5. 7

As will be evident to those skilled in the art, various modifications of this invention can be made or followed in the light of the foregoing disclosure and discussion without departing from the spirit or the scope of the disclosure.

We claim:

1. A resin composition of sulfur dioxide and an unsaturated compound which reacts with sulfur dioxide to form a heteropolymeric resin, consisting essentialy of a nitrile boiling above 250 F., having a molecular weight of between 80 and and 1000, and having no aliphatic hydrocarbon group containing more than six carbon atoms and an unsaturated organic compound-sulfur dioxide resin being present in a ratio of parts by weight of nitrile to resin within the range'of 1:100 to 150:100.

2. The composition of claim 1, wherein said nitrile and said unsaturated organic compoundsulfur dioxide resin are present in a ratio of parts by weight within the range of 5:100 to 80:100.

3. An olefin-sulfur dioxide resin composition consisting essentially of a nitrile boiling above 250 F., having a molecular weight of between 80 and 1000, having no aliphatic hydrocarbon group containing more than six carbon atoms and an olefin-sulfur dioxide resin latex having a pH value not above 8, said nitrile and said olefinsulfur dioxide resin being present in a ratio of parts by weight within the range of 1:100 to 150:100.

4. The composition of claim 3, wherein said nitrile and said olefin-sulfur dioxide resin are present in a ratio of parts by weight within the range of 5:100 to 80:100.

5. The composition of claim 3, wherein saidnitrile is an aliphatic nitrile.

6. The composition of claim 3, nitrile is adiponitrile.

7. The composition of claim 3, nitrile is an aromatic substituted trile.

8. The composition of claim 3, nitrile is benzonitrile.

9. The composition of claim 3, nitrile is phenylacetonitrile.

10. The composition of claim 3, wherein said nitrile is an aromatic substituted aliphatic nitrile in which the aromatic ring is substituted by aliphatic groups.

11. A method of producing olefin-sulfur dioxide resin compositions which comprises emulsiiying an olefinic organic material in an aqueone solution of sulfur dioxide, said sulfur dioxide being in an amount stoichiometrically in excess of said olefin; efiecting a reaction between said sulfur dioxide and said olefinic organic comwherein said aliphatic niwherein said wherein said wherein said pound to produce a heteropolymeric reaction product; and mixing a resin latex resulting from said reaction with a nitrile in a ratio within the nitrile to resin latex range of between 1:100 and 150:100, said nitrile boiling above 250 F., having a molecular weight of between and 1000, and having no aliphatic hydrocarbon group containing more than six carbon atoms, to form a stable latex.

12. The method of claim 11, wherein said stable latex is coagulated and recovered.

13. The method of claim 11, wherein the ratio of nitrile to resin latex is in the range of 5:100 to 80:100.

14. A resin composition of sulfur dioxide and an unsaturated compound which reacts with sulfur dioxide to form a heteropolymeric resin, consisting essentially of a nitrile boiling above 170 F., having a molecular weight of between 40 and 1000, and having no aliphatic hydrocarbon group containing more than twenty carbon atoms and an unsaturated organic compound-sulfur dioxide resin being present in a ratio of parts by weight of nitrile to resin within the range of 0.5: to :100.

15. The composition of claim 14, wherein said nitrile and said olefin-sulfur dioxide resin are present in a ratio of parts by weight within the range of 0.5 100 to 15:100.

16. The composition of claim 15, wherein said nitrile is diphenylacetonitrile.

18. The composition of claim 19, wherein said nitrile boils above 245 F.

19. A resin composition of sulfur dioxide and an unsaturated compound which reacts with sulfur dioxide to form a heteropolymeric resin, consisting essentially of a nitrile having the general formula RCN wherein R is selected from the group consisting of alkyl; cycloalkyl; alkenyl; hydrocarbon aromatic; substituted alkyl, cycloalkyl, and alkenyl groups wherein the substituents are selected from the group consisting of cyano and halogen radicals selected from the group consisting of fluorine, chlorine, and bromine; and substituted hydrocarbon aromatics wherein the substituents are selected from the group consisting of alkyl and halogen radicals selected from the group consisting of fluorine, chlorine, and bromine; said nitrile boiling above F., having a molecular weight of between 40 and 1000, and having no aliphatic hydrocarbon WILLIE W.-- CROUCH. JOHN F. HOWE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Snow Jan. 18, 1944 v 

1. A RESIN COMPOSITION OF SULFUR DIOXIDE AND AN UNSATURATED COMPOUND WHICH REACTS WITH SULFUR DIOXIDE TO FORM A HETEROPOLYMERIC RESIN, CONSISTING ESSENTIALLY OF A NITRILE BOILING ABOVE 250* F., HAVING A MOLECULAR WEIGHT OF BETWEEN 80 AND AND 1000, AND HAVING NO ALIPHATIC HYDROCARBON GROUP CONTAINING MORE THAN SIX CARBON ATOMS AND AN UNSATURATED ORGANIC COMPOUND-SULFUR DIOXIDE RESIN BEING PRESENT IN A RATIO OF PARTS BY WEIGHT OF NITRILE TO RESIN WITHIN THE RANGE OF 1:100 TO 150:100. 